U.S. patent application number 17/362874 was filed with the patent office on 2021-10-21 for optical switching apparatus and system, and power calculation method.
This patent application is currently assigned to HUAWEI TECHNOLOGIES CO.,LTD.. The applicant listed for this patent is HUAWEI TECHNOLOGIES CO.,LTD.. Invention is credited to Chunhui Zhang.
Application Number | 20210328702 17/362874 |
Document ID | / |
Family ID | 1000005739873 |
Filed Date | 2021-10-21 |
United States Patent
Application |
20210328702 |
Kind Code |
A1 |
Zhang; Chunhui |
October 21, 2021 |
OPTICAL SWITCHING APPARATUS AND SYSTEM, AND POWER CALCULATION
METHOD
Abstract
This application provides an optical switching apparatus. The
apparatus includes: a first optical switch, L first wavelength
division multiplexers/demultiplexers, L second wavelength division
multiplexers/demultiplexers, a beam generation apparatus connected
to the L first wavelength division multiplexers/demultiplexers, and
a detection apparatus connected to the L second wavelength division
multiplexers/demultiplexers. One of a plurality of multiplexing
ports of the first wavelength division multiplexer/demultiplexer is
a signal light port, and a remaining multiplexing port is connected
to the beam generation apparatus. A plurality of demultiplexing
ports of the first wavelength division multiplexer/demultiplexer
are connected to the first optical switch. One of a plurality of
multiplexing ports of the second wavelength division
multiplexer/demultiplexer is a signal light port, and a remaining
multiplexing port is connected to the detection apparatus. A
plurality of demultiplexing ports of the second wavelength division
multiplexer/demultiplexer are connected to the first optical
switch.
Inventors: |
Zhang; Chunhui; (Wuhan,
CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HUAWEI TECHNOLOGIES CO.,LTD. |
Shenzhen |
|
CN |
|
|
Assignee: |
HUAWEI TECHNOLOGIES
CO.,LTD.
Shenzhen
CN
|
Family ID: |
1000005739873 |
Appl. No.: |
17/362874 |
Filed: |
June 29, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
PCT/CN2019/129729 |
Dec 30, 2019 |
|
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17362874 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04Q 11/0005 20130101;
H04J 14/0221 20130101; H04J 14/0202 20130101; H04Q 2011/0016
20130101 |
International
Class: |
H04J 14/02 20060101
H04J014/02; H04Q 11/00 20060101 H04Q011/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 29, 2018 |
CN |
201811640720.9 |
Claims
1. An optical switching apparatus, comprising: a first optical
switch, L first wavelength division multiplexers/demultiplexers and
L second wavelength division multiplexers/demultiplexers connected
to the first optical switch, and L is a positive integer; the L
first wavelength division multiplexers/demultiplexers and the L
second wavelength division multiplexers/demultiplexers each
comprise a plurality of multiplexing ports and a plurality of
demultiplexing ports; one first port of the plurality of
multiplexing ports of the first wavelength division
multiplexer/demultiplexer is a signal light port, a remaining
multiplexing port is connected to the beam generation apparatus,
and the plurality of demultiplexing ports of the first wavelength
division multiplexer/demultiplexer are connected to the first
optical switch; one of the plurality of multiplexing ports of the
second wavelength division multiplexer/demultiplexer is a signal
light port, a remaining multiplexing port is connected to a
detection apparatus, and the plurality of demultiplexing ports of
the second wavelength division multiplexer/demultiplexer are
connected to the first optical switch; a beam generation apparatus
connected to the L first wavelength division
multiplexers/demultiplexers, the beam generation apparatus
configured to input first laser light to a multiplexing port other
than a signal light port in a plurality of multiplexing ports of
any first wavelength division multiplexer/demultiplexer; the
detection apparatus is connected to the L second wavelength
division multiplexers/demultiplexers and is configured to obtain an
output power value of the first laser light.
2. The apparatus according to claim 1, wherein the beam generation
apparatus comprises a tunable laser and a second optical switch,
wherein: the second optical switch is connected to both the tunable
laser and the remaining multiplexing port of the first wavelength
division multiplexer/demultiplexer, and is configured to switch
laser light output by the tunable laser to a target multiplexing
port of the first wavelength division
multiplexer/demultiplexer.
3. The apparatus according to claim 2, wherein the detection
apparatus further comprises a detector and a coupler, wherein: the
coupler is connected to both the detector and the remaining
multiplexing port of the second wavelength division
multiplexer/demultiplexer, and is configured to couple laser light
output through the remaining multiplexing port of the second
wavelength division multiplexer/demultiplexer to the detector.
4. The apparatus according to claim 1, wherein the beam generation
apparatus comprises a plurality of first tunable lasers, and each
first tunable laser in the plurality of first tunable lasers is
connected to one multiplexing port other than the signal light port
of each of the L first wavelength division
multiplexers/demultiplexers.
5. The apparatus according to claim 4, wherein the detection
apparatus comprises a plurality of detectors, and each detector is
connected to one multiplexing port other than the signal light port
of each of the L second wavelength division
multiplexers/demultiplexers.
6. The apparatus according to claim 1, wherein the first optical
switch further comprises M first tributary ports, and the optical
switching apparatus further comprises a third optical switch,
wherein the third optical switch is connected to both the beam
generation apparatus and the M first tributary ports, and wherein M
is a positive integer.
7. The apparatus according to claim 6, wherein when the M first
tributary ports correspond to the L first wavelength division
multiplexers/demultiplexers, the optical switching apparatus
further comprises a plurality of circulators, wherein: a first port
of each circulator in the plurality of circulators is connected to
the beam generation apparatus, a second port of each circulator is
connected to one multiplexing port other than the signal light port
of the first wavelength division multiplexer/demultiplexer, and
wherein a third port of each circulator is connected to the
detection apparatus.
8. The apparatus according to claim 6, wherein the first optical
switch further comprises N second tributary ports, and the optical
switching apparatus further comprises a fourth optical switch,
wherein the fourth optical switch is connected to both the beam
generation apparatus and the N second tributary ports of the first
optical switch, and wherein N is a positive integer.
9. The apparatus according to claim 1, wherein the first optical
switch further comprises M first tributary ports, and the optical
switching apparatus comprises a multi-wavelength laser source,
wherein a plurality of output ports of the multi-wavelength laser
source are respectively connected to the M first tributary
ports.
10. The apparatus according to claim 1, wherein the apparatus
further comprises: a processor connected to an output port of the
detection apparatus, and configured to: obtain an output power of
the laser light; and determine an insertion loss of the first
optical switch based on the output power and an input power.
11. A power calculation method for an optical switching apparatus,
the method comprising: inputting, by a beam generation apparatus,
first laser light to a multiplexing port other than a signal light
port in a plurality of multiplexing ports of any first wavelength
division multiplexer/demultiplexer in a L first wavelength division
multiplexers/demultiplexers; inputting, by the first wavelength
division multiplexer/demultiplexer that receives the first laser
light, the first laser light through one of a plurality of
demultiplexing ports of the first wavelength division
multiplexer/demultiplexer to a first optical switch; inputting, by
the first optical switch, the first laser light to a corresponding
demultiplexing port of any second wavelength division
multiplexer/demultiplexer in L second wavelength division
multiplexers/demultiplexers; inputting, by the second wavelength
division multiplexer/demultiplexer that receives the first laser
light, the first laser light through one multiplexing port other
than a signal light port in a plurality of multiplexing ports of
the second wavelength division multiplexer/demultiplexer to the
detection apparatus; and obtaining, by the detection apparatus, an
output power value of the first laser light.
12. The method according to claim 11, wherein the beam generation
apparatus comprises a tunable laser and a second optical switch;
and the inputting, by the beam generation apparatus, first laser
light to a multiplexing port other than a signal light port in a
plurality of multiplexing ports of any first wavelength division
multiplexer/demultiplexer in the L first wavelength division
multiplexers/demultiplexers comprises: generating, by the tunable
laser, the first laser light and inputting the first laser light to
the second optical switch; and switching, by the second optical
switch, the first laser light to a target multiplexing port of the
any first wavelength division multiplexer/demultiplexer.
13. The method according to claim 12, wherein the detection
apparatus further comprises a detector and a coupler, and the
obtaining, by the detection apparatus, an output power of the first
laser light comprises: coupling, by the coupler, the first laser
light from the second wavelength division multiplexer/demultiplexer
to the detector; and calculating, by the detector, the output power
of the first laser light output by the second wavelength division
multiplexer/demultiplexer.
14. The method according to claim 11, wherein the beam generation
apparatus comprises a plurality of first tunable lasers, and each
first tunable laser in the plurality of first tunable lasers is
connected to one multiplexing port other than the signal light port
of each of the L first wavelength division
multiplexers/demultiplexers; and the inputting, by the beam
generation apparatus, the first laser light to the multiplexing
port other than the signal light port in the plurality of
multiplexing ports of any first wavelength division
multiplexer/demultiplexer in the L first wavelength division
multiplexers/demultiplexers comprises inputting, by the each first
tunable laser, the first laser light to the connected multiplexing
port.
15. The method according to claim 14, wherein the detection
apparatus comprises a plurality of detectors, and each detector in
the plurality of detectors is connected to the one multiplexing
port other than the signal light port of the each of the L second
wavelength division multiplexers/demultiplexers; and the obtaining,
by the detection apparatus, the output power of the first laser
light comprises detecting, by the each detector, the output power
of the first laser light output through the connected multiplexing
port.
16. The method according to claim 11, wherein the first optical
switch further comprises M first tributary ports, and the optical
switching apparatus further comprises a third optical switch,
wherein the third optical switch is connected to both the beam
generation apparatus and the M first tributary ports, and wherein M
is a positive integer; the method further comprising: inputting, by
the beam generation apparatus, second laser light to the M first
tributary ports through the third optical switch; inputting, by the
first optical switch, the second laser light to a target
demultiplexing port of one of the L first wavelength division
multiplexers/demultiplexers; inputting, by the first wavelength
division multiplexer/demultiplexer that receives the second laser
light, the second laser light to the detection apparatus; and
obtaining, by the detection apparatus, an output power value of the
second laser light.
17. The method according to claim 16, wherein when the M first
tributary ports correspond to the L first wavelength division
multiplexers/demultiplexers, the optical switching apparatus
further comprises a plurality of circulators, wherein a first port
of each circulator in the plurality of circulators is connected to
the beam generation apparatus, a second port of each circulator is
connected to one multiplexing port other than the signal light port
of the first wavelength division multiplexer/demultiplexer, and a
third port of each circulator is connected to the detection
apparatus; and the inputting, by the first wavelength division
multiplexer/demultiplexer that receives the second laser light, the
second laser light to the detection apparatus comprises: inputting,
by the first wavelength division multiplexer/demultiplexer that
receives the second laser light, the second laser light to the
second port of the circulator; and inputting, by the circulator,
the second laser light through the third port to the detection
apparatus.
18. The method according to claim 11, wherein the method further
comprises: inputting, by the beam generation apparatus, second
laser light to M first tributary ports of the first optical switch
through a third optical switch, wherein M is a positive integer;
inputting, by the first optical switch, the second laser light to a
target demultiplexing port of one of the L second wavelength
division multiplexers/demultiplexers; inputting, by the second
wavelength division multiplexer/demultiplexer that receives the
second laser light, the second laser light to the detection
apparatus; and obtaining, by the detection apparatus, an output
power of the second laser light.
19. The method according to claim 18, wherein the method further
comprises: receiving, by the M first tributary ports comprised in
the first optical switch, laser light from a multi-wavelength laser
source.
20. The method according to claim 11, wherein the method further
comprises: obtaining, by a processor, an output power value of the
laser light that is obtained by the detection apparatus, and
calculating a power loss of the laser light based on an input power
of the laser light.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of International
Application No. PCT/CN2019/129729, filed on Dec. 30, 2019, which
claims priority to Chinese Patent Application No. 201811640720.9,
filed on Dec. 29, 2018. The disclosures of the aforementioned
applications are hereby incorporated by reference in their
entireties.
TECHNICAL FIELD
[0002] Embodiments of this application relate to the field of
optical communications technologies, and in particular, to an
optical switching apparatus, an optical switching system, and a
power calculation method based on the apparatus.
BACKGROUND
[0003] With the development of a dense wavelength division
multiplexing (DWDM) technology, a speed and a capacity of
information transmission on an optical fiber communications link
are increasing, and demands for a speed and a capacity of
information exchange in an optical communications network (such as
a metropolitan area network or a data center) are increasing
accordingly. All-optical switching system has become a development
trend of the optical communications network.
[0004] A networking manner of an all-optical communications network
is an optical cross-connect (OXC) optical switching system. An
insertion loss of any node in the OXC optical switching system is
usually detected by using an optical splitting detection method. As
shown in FIG. 1, one optical splitter 103 (a 5% optical splitter is
used as an example in FIG. 1) is connected in series on each
optical channel between an AWG 102 and an optical switch 101, and
one photodetector (PD) 104 is connected to an optical splitting
port of the optical splitter 103. One optical splitter 106 is also
connected in series to each tributary port of the optical switch
101, and one PD 105 is connected to an optical splitting port of
the optical splitter 106.
[0005] When service light passes through the optical channel
between the AWG 102 and the optical switch 101, a part of the
service light enters the PD 104 through the optical splitter 103.
Based on an optical power detected by the PD 104 and a split ratio
of the optical splitter 103, an input optical power of the optical
switch 101 and an output optical power of the optical switch 101
may be calculated. Further, an insertion loss of the optical switch
may be calculated based on the input optical power of the optical
switch 101 and the output optical power of the optical switch
101.
[0006] However, in FIG. 1, the insertion loss of the optical switch
can be detected only when service light exists on an optical
channel. For an optical channel without service light, because the
PD cannot detect an optical power, the insertion loss of the
optical switch cannot be detected.
SUMMARY
[0007] Embodiments of this application provide an optical switching
apparatus, to resolve a problem of how to detect an insertion loss
of an optical switch for an optical channel without service
light.
[0008] To resolve the foregoing technical problem, the embodiments
of this application provide the following technical solutions.
[0009] According to a first aspect, an embodiment of this
application provides an optical switching apparatus, including: a
first optical switch, L first wavelength division
multiplexers/demultiplexers and L second wavelength division
multiplexers/demultiplexers, a beam generation apparatus connected
to the L first wavelength division multiplexers/demultiplexers, and
a detection apparatus connected to the L second wavelength division
multiplexers/demultiplexers, where the L first wavelength division
multiplexers/demultiplexers and the L second wavelength division
multiplexers/demultiplexers are connected to the first optical
switch, and L is a positive integer. The first wavelength division
multiplexer/demultiplexer and the second wavelength division
multiplexer/demultiplexer each include a plurality of multiplexing
ports and a plurality of demultiplexing ports. One of the plurality
of multiplexing ports of the first wavelength division
multiplexer/demultiplexer is a signal light port, and a remaining
multiplexing port is connected to the beam generation apparatus.
The plurality of demultiplexing ports of the first wavelength
division multiplexer/demultiplexer are connected to the first
optical switch. One of the plurality of multiplexing ports of the
second wavelength division multiplexer/demultiplexer is a signal
light port, and a remaining multiplexing port is connected to the
detection apparatus. The plurality of demultiplexing ports of the
second wavelength division multiplexer/demultiplexer are connected
to the first optical switch.
[0010] According to a second aspect, an embodiment of this
application provides an optical switching system. The optical
switching system includes at least two optical switching
apparatuses described in any one of the first aspect or the
possible implementations of the first aspect.
[0011] According to a third aspect, an embodiment of this
application provides a power calculation method for laser light,
where the method is used for an optical switching apparatus. The
optical switching apparatus includes: a first optical switch, L
first wavelength division multiplexers/demultiplexers and L second
wavelength division multiplexers/demultiplexers, a beam generation
apparatus connected to the L first wavelength division
multiplexers/demultiplexers, and a detection apparatus connected to
the L second wavelength division multiplexers/demultiplexers, where
the L first wavelength division multiplexers/demultiplexers and the
L second wavelength division multiplexers/demultiplexers are
connected to the first optical switch, and L is a positive integer.
The method includes: The beam generation apparatus inputs first
laser light to a multiplexing port other than a signal light port
in a plurality of multiplexing ports of any first wavelength
division multiplexer/demultiplexer in the L first wavelength
division multiplexers/demultiplexers. The first wavelength division
multiplexer/demultiplexer that receives the first laser light
inputs the first laser light through one of a plurality of
demultiplexing ports of the first wavelength division
multiplexer/demultiplexer to the first optical switch. The first
optical switch inputs the first laser light to a corresponding
demultiplexing port of any second wavelength division
multiplexer/demultiplexer in the L second wavelength division
multiplexers/demultiplexers. The second wavelength division
multiplexer/demultiplexer that receives the first laser light
inputs the first laser light through one multiplexing port other
than the signal light port in a plurality of multiplexing ports of
the second wavelength division multiplexer/demultiplexer to the
detection apparatus. The detection apparatus obtains an output
power of the first laser light.
BRIEF DESCRIPTION OF DRAWINGS
[0012] FIG. 1 is a schematic diagram of any node of an optical
switching system according to an embodiment of this
application;
[0013] FIG. 2 is a schematic diagram of a structure of an optical
switching system according to an embodiment of this
application;
[0014] FIG. 3 is a schematic diagram of an optical path of a
pass-through channel according to an embodiment of this
application;
[0015] FIG. 4 is a schematic diagram of an optical path of a
wavelength-adding channel according to an embodiment of this
application;
[0016] FIG. 5 is a schematic diagram of an optical path of a
wavelength-dropping channel according to an embodiment of this
application;
[0017] FIG. 6 to FIG. 17 are schematic diagrams of a structure of
an optical switching apparatus according to an embodiment of this
application;
[0018] FIG. 18 is a schematic flowchart 1 of a power calculation
method according to an embodiment of this application; and
[0019] FIG. 19A and FIG. 19B are a schematic flowchart 2 of a power
calculation method according to an embodiment of this
application.
DESCRIPTION OF EMBODIMENTS
[0020] To clearly describe the technical solutions in embodiments
of this application, terms such as "first" and "second" are used in
the embodiments of this application to distinguish between same
items or similar items that have basically same functions and
purposes. For example, first laser light and second laser light are
merely intended to distinguish between different laser light, and
do not limit a sequence of the first laser light and the second
laser light. Persons skilled in the art may understand that the
terms such as "first" and "second" do not constitute a limitation
on a quantity or an execution sequence, and that the terms such as
"first" and "second" do not indicate a definite difference.
[0021] It should be noted that, in this application, the word
"exemplary" or "for example" is used to represent giving an
example, an illustration, or a description. Any embodiment or
design scheme described as an "exemplary" or "for example" in this
application should not be explained as being more preferred or
having more advantages than another embodiment or design scheme.
Exactly, use of the word "exemplary" or "example" is intended to
present a relative concept in a specific manner.
[0022] In this application, "at least one" refers to one or more,
and "a plurality of" refers to two or more. The term "and/or"
describes an association relationship for describing associated
objects and represents that three relationships may exist. For
example, A and/or B may represent the following cases: Only A
exists, both A and B exist, and only B exists, where A and B may be
singular or plural. The character "I" generally indicates an "or"
relationship between the associated objects. "At least one of the
following" or a similar expression thereof indicates any
combination of the following, including any combination of one or
more of the following. For example, at least one of a, b, or c may
indicate: a, b, c, a and b, a and c, b and c, or a, b, and c, where
a, b, and c may be singular or plural.
[0023] As shown in FIG. 2, in an OXC optical switching system, any
node includes an optical switch 10 and at least one arrayed
waveguide grating (AWG) 20. The AWG 20 includes one multiplexing
port 201 and N demultiplexing ports 202. The multiplexing port 201
serves as a line port and is used to communicate with another node
in the OXC optical switching system, and the demultiplexing port
202 is connected to the optical switch 10. A port that is of the
optical switch 10 and that is not connected to the AWG 20 serves as
a tributary port and is used to communicate with a local service
board.
[0024] An embodiment of this application provides an optical
switching apparatus, including L first wavelength division
multiplexers/demultiplexers and L second wavelength division
multiplexers/demultiplexers. Each wavelength division
multiplexer/demultiplexer has a signal light port and a remaining
multiplexing port. In this way, laser light may be input to the
remaining multiplexing port of the L first wavelength division
multiplexers/demultiplexers by a beam generation apparatus, and
then a first optical switch inputs the received laser light to
demultiplexing ports of the L second wavelength division
multiplexers/demultiplexers. Then, any second wavelength division
multiplexer/demultiplexer that receives the laser light and that is
in the L second wavelength division multiplexers/demultiplexers
sends the received laser light through a remaining multiplexing
port of the second wavelength division multiplexer/demultiplexer to
a detection apparatus, so that the detection apparatus obtains an
output power of the output laser light. In comparison with the
conventional technology, the optical switching apparatus provided
in this embodiment of this application can still obtain the output
power of the laser light when there is no signal light, so as to
obtain an insertion loss of the first optical switch based on an
input power of the laser light and the output power of the laser
light.
[0025] The following provides related explanations of terms used in
the embodiments with reference to the embodiments of this
application.
[0026] (1) A pass-through channel is an optical signal channel
between line ports. To be specific, laser light is input to a first
optical switch by a first wavelength division
multiplexer/demultiplexer, and then is input to a second wavelength
division multiplexer/demultiplexer by the first optical switch. The
laser light is then output by the second wavelength division
multiplexer/demultiplexer. Alternatively, laser light is input to a
first optical switch by a second wavelength division
multiplexer/demultiplexer, and then is input to a first wavelength
division multiplexer/demultiplexer by the first optical switch. The
laser light is then output by the first wavelength division
multiplexer/demultiplexer.
[0027] It should be noted that, on the pass-through channel, a
transmission direction of detection light in the first optical
switch may be the same as or opposite to a transmission direction
of signal light in the first optical switch. In FIG. 3 in the
following embodiment, a case in which a transmission direction of
detection light in an optical switch may be opposite to a
transmission direction of signal light in the optical switch is
used as an example.
[0028] For example, as shown in FIG. 3, the second wavelength
division multiplexer/demultiplexer is an AWG 3, and the first
wavelength division multiplexer/demultiplexer is an AWG 2. Signal
light with a wavelength of .lamda..sub.3 is input through a signal
light port of the AWG 3, and is output through a demultiplexing
port 3 of the AWG 3. After passing through the first optical
switch, the signal light with the wavelength of .lamda..sub.3 is
input through a demultiplexing port 3 of the AWG 2, and is output
through a signal light port of the AWG 2. Detection light with a
wavelength of .lamda.'.sub.3 is input through a multiplexing port
that is used as a detection light port and that is of the AWG 2,
and is output through the demultiplexing port 3 of the AWG 2. After
passing through the first optical switch, the detection light with
the wavelength of .lamda.'.sub.3 is input through the
demultiplexing port 3 of the AWG 3, is output through a
multiplexing port of the AWG 3, and is received and detected by a
detector. The detector detects an output power of the detection
light with the wavelength of .lamda.'.sub.3. In this way, an
insertion loss 1 of the detection light with the wavelength of
.lamda.'.sub.3 on the entire pass-through channel can be obtained
based on the output power of the detection light with the
wavelength of .lamda.'.sub.3 and an input power of the detection
light with the wavelength of .lamda.'.sub.3. By subtracting an
insertion loss of components through which the detection light with
the wavelength of .lamda.'.sub.3 passes on an optical path of the
pass-through channel (for example, an insertion loss of the AWG 2
and the AWG 3) from the insertion loss 1, an insertion loss of the
detection light with the wavelength of .lamda.'.sub.3 on the
pass-through channel in the first optical switch can be obtained.
Because the first optical switch is insensitive to a wavelength,
the insertion loss of the detection light with the wavelength of
.lamda.'.sub.3 on the pass-through channel in the first optical
switch may be approximately considered as a loss value of the
signal light with the wavelength of .lamda..sub.3 in the first
optical switch.
[0029] By adjusting a wavelength of a tunable light source, an
insertion loss of signal light of an optical signal channel
corresponding to the AWG 2 can be detected.
[0030] (2) A wavelength-adding channel is an optical signal channel
from a tributary port to a line port. To be specific, laser light
is input to a first optical switch through a first tributary port
or a second tributary port, and then is input to a second
wavelength division multiplexer/demultiplexer or a first wavelength
division multiplexer/demultiplexer by the first optical switch. The
laser light is then output by the second wavelength division
multiplexer/demultiplexer or the first wavelength division
multiplexer/demultiplexer.
[0031] For example, a detection method for the wavelength-adding
channel is shown in FIG. 4. A transmission direction of detection
light in the first optical switch may be the same as or opposite to
a transmission direction of signal light in the first optical
switch. In FIG. 4, a case in which a transmission direction of
detection light is the same as a transmission direction of signal
light is used as an example.
[0032] Signal light with a wavelength of .lamda..sub.2 is input
through a 95% port of a coupler, enters one first tributary port of
the first optical switch, and is input through a demultiplexing
port 2 of an AWG 1 after passing through the first optical switch.
The signal light with the wavelength of .lamda..sub.2 is output
through a signal light port of the AWG 1.
[0033] Detection light with a wavelength of .lamda.'.sub.2 is input
through a 5% port of the coupler, and enters one first tributary
port of the first optical switch. After passing through the first
optical switch, the detection light with the wavelength of
.lamda.'.sub.2 is input through the demultiplexing port 2 of the
AWG 1, is output through a multiplexing port of the AWG 1, and is
received and detected by a detector. In this way, the detector can
detect an output power of the detection light with the wavelength
of .lamda.'.sub.2.
[0034] Finally, based on the output power that is of the detection
light with the wavelength of .lamda.'.sub.2 and that is detected by
the detector and an input power of the detection light with the
wavelength of .lamda.'.sub.2, an insertion loss 1 of the detection
light with the wavelength of .lamda.'.sub.2 on the
wavelength-adding channel can be obtained. By subtracting an
insertion loss of components through which the detection light with
the wavelength of .lamda.'.sub.2 passes on an optical path of the
wavelength-adding channel (for example, an insertion loss of the
AWG 1 and a 5% coupler) from the insertion loss 1 of the detection
light with the wavelength of .lamda.'.sub.2 on the
wavelength-adding channel, an insertion loss of the detection light
with the wavelength of .lamda.'.sub.2 on the wavelength-adding
channel in the first optical switch can be obtained. Because the
first optical switch is insensitive to a wavelength, the insertion
loss of the detection light with the wavelength of .lamda.'.sub.2
on the wavelength-adding channel in the first optical switch may be
approximately considered as an insertion loss of the signal light
with the wavelength of .lamda..sub.2 on the wavelength-adding
channel in the first optical switch.
[0035] (3) A wavelength-dropping channel is an optical signal
channel from a line port to a tributary port. To be specific, laser
light is input to a first optical switch by a second wavelength
division multiplexer/demultiplexer or a first wavelength division
multiplexer/demultiplexer, and then is input to a first tributary
port or a second tributary port by the first optical switch. The
laser light is then output through the first tributary port or the
second tributary port.
[0036] For example, a detection method for the wavelength-dropping
channel is shown in FIG. 5. On the wavelength-dropping channel, a
transmission direction of detection light and a transmission
direction of signal light in the first optical switch need to be
opposite.
[0037] Signal light with a wavelength of .lamda..sub.2 is input
through a signal light port of an AWG 2, output through a
demultiplexing port 2, output through one tributary port of the
first optical switch after passing through the first optical
switch, and transmitted to a local service board after passing
through a coupler.
[0038] Detection light with a wavelength of .lamda.'.sub.2 is input
through a 5% port of the coupler, and enters a tributary port of
the first optical switch. After passing through the first optical
switch, the detection light with the wavelength of .lamda.'.sub.2
is input through a demultiplexing port 2 of the AWG 2, is output
through a multiplexing port of the AWG 2, and is received and
detected by a detector. In this way, the detector can detect and
obtain an output power of the detection light with the wavelength
of .lamda.'.sub.2.
[0039] Finally, based on the output power that is of the detection
light with the wavelength of .lamda.'.sub.2 and that is detected by
the detector and an input power of the detection light with the
wavelength of .lamda.'.sub.2, an insertion loss 1 of the detection
light with the wavelength of .lamda.'.sub.2 on the
wavelength-dropping channel can be obtained. By subtracting an
insertion loss of components through which the detection light with
the wavelength of .lamda.'.sub.2 passes on an optical path of the
wavelength-dropping channel (for example, an insertion loss of the
AWG 1 and a 5% coupler) from the insertion loss 1 of the detection
light with the wavelength of .lamda.'.sub.2 on the
wavelength-dropping channel, an insertion loss of the detection
light with the wavelength of .lamda.'.sub.2 on the
wavelength-dropping channel in the first optical switch can be
obtained. Because the first optical switch is insensitive to a
wavelength, the insertion loss of the detection light with the
wavelength of .lamda.'.sub.2 on the wavelength-dropping channel in
the first optical switch may be approximately considered as an
insertion loss of the signal light with the wavelength of
.lamda..sub.2 on the wavelength-dropping channel in the first
optical switch.
[0040] It should be noted that, in this embodiment of this
application, the insertion loss of the signal light with the
wavelength of .lamda..sub.2 in the first optical switch can be
obtained based on the insertion loss of the detection light on the
wavelength-dropping channel/the wavelength-adding channel/the
pass-through channel in the first optical switch. If the insertion
loss of the signal light with the wavelength of .lamda..sub.2 on
the wavelength-dropping channel/wavelength-adding
channel/pass-through channel needs to be calculated, an insertion
loss of components through which the signal light with the
wavelength of .lamda..sub.2 passes on the optical path of the
wavelength-dropping channel/wavelength-adding channel/pass-through
channel may be added to the insertion loss of the signal light with
the wavelength of .lamda..sub.2 in the first optical switch.
[0041] It should be understood that the wavelength-dropping
channel, the wavelength-adding channel, and the pass-through
channel in the embodiments of this application are transmitted in a
unit of a wavelength.
[0042] It should be noted that an arrow in the embodiments of this
application represents a propagation direction of signal light or
detection light.
[0043] FIG. 6 shows an optical switching apparatus 200 according to
an embodiment of this application. The optical switching apparatus
200 includes: a first optical switch 201, L first wavelength
division multiplexers/demultiplexers 202 connected to the first
optical switch 201 (for example, a first wavelength division
multiplexer/demultiplexer 21, a first wavelength division
multiplexer/demultiplexer 22, . . . , and a first wavelength
division multiplexer/demultiplexer 2L shown in FIG. 6), L second
wavelength division multiplexers/demultiplexers 203 connected to
the first optical switch 201 (for example, a second wavelength
division multiplexer/demultiplexer 31, a second wavelength division
multiplexer/demultiplexer 32, . . . , and a second wavelength
division multiplexer/demultiplexer 3L in FIG. 6), a beam generation
apparatus 204 connected to the L first wavelength division
multiplexers/demultiplexers 202, and a detection apparatus 205
connected to the L second wavelength division
multiplexers/demultiplexers 203. L is a positive integer.
[0044] The first wavelength division multiplexer/demultiplexer 202
includes a plurality of multiplexing ports and a plurality of
demultiplexing ports (for example, a multiplexing port 2021, a
multiplexing port 2022, and a demultiplexing port 2023 shown in
FIG. 6). It should be understood that FIG. 6 shows two multiplexing
ports, and in an actual process, there may be three or more
multiplexing ports.
[0045] The second wavelength division multiplexer/demultiplexer 203
includes a plurality of multiplexing ports and a plurality of
demultiplexing ports (for example, a multiplexing port 2031, a
multiplexing port 2032, and a demultiplexing port 2033 shown in
FIG. 6). One of the plurality of multiplexing ports of the first
wavelength division multiplexer/demultiplexer 202 is a signal light
port (for example, as shown in FIG. 6, the multiplexing port 2021
is a signal light port), and a remaining multiplexing port is
connected to the beam generation apparatus 204. The plurality of
demultiplexing ports of the first wavelength division
multiplexer/demultiplexer 202 are connected to the first optical
switch 201. One of the plurality of multiplexing ports of the
second wavelength division multiplexer/demultiplexer 203 is a
signal light port (for example, the multiplexing port 2031 is a
signal light port), and a remaining multiplexing port is connected
to the detection apparatus 205. The plurality of demultiplexing
ports of the second wavelength division multiplexer/demultiplexer
203 are connected to the first optical switch 201. It should be
understood that FIG. 6 shows two multiplexing ports, and in an
actual process, there may be three or more multiplexing ports.
[0046] It should be understood that the signal light port is used
to input signal light or output signal light. For example, the
signal light port of the first wavelength division
multiplexer/demultiplexer 202 is used to input signal light. The
signal light port of the second wavelength division
multiplexer/demultiplexer 203 is used to output signal light.
[0047] In this embodiment of this application, a plurality of
multiplexing ports of any first wavelength division
multiplexer/demultiplexer 202 in the L first wavelength division
multiplexers/demultiplexers 202 and a plurality of multiplexing
ports of any second wavelength division multiplexer/demultiplexer
203 in the L second wavelength division multiplexers/demultiplexers
203 may serve as line ports and are used to communicate with
another node.
[0048] In this embodiment of this application, a signal light port
of any first wavelength division multiplexer/demultiplexer 202 in
the L first wavelength division multiplexers/demultiplexers 202 and
a signal light port of any second wavelength division
multiplexer/demultiplexer 203 in the L second wavelength division
multiplexers/demultiplexers 203 use DWDM signal light.
[0049] It should be understood that, if the beam generation
apparatus 204 is further configured to provide signal light for the
L first wavelength division multiplexers/demultiplexers 202, the
beam generation apparatus 204 is further connected to a signal
light port of each first wavelength division
multiplexer/demultiplexer 202 in the L first wavelength division
multiplexers/demultiplexers 202.
[0050] The beam generation apparatus 204 in this embodiment of this
application is configured to provide detection light for the
remaining multiplexing port of the L first wavelength division
multiplexers/demultiplexers 202. The remaining multiplexing port in
the embodiments of this application may be referred to as a
detection light port.
[0051] It should be understood that the signal light in the
embodiments of this application refers to laser light that is
modulated and that has a service signal. The detection light in the
embodiments of this application refers to laser light that is not
modulated and that does not have a service signal.
[0052] For example, the first wavelength division
multiplexer/demultiplexer 202 and the second wavelength division
multiplexer/demultiplexer 203 in this embodiment of this
application may be arrayed waveguide gratings (AWG).
[0053] The optical switch in the embodiments of this application is
a key component for implementing an all-optical switching system,
and can implement functions at an all-optical layer such as route
selection, wavelength selection, optical cross-connection, and
self-healing protection. Currently, optical switches mainly include
a conventional optical switch of a mechanical structure, a
micro-electrical-mechanical system (MEMS) optical switch, a liquid
crystal optical switch, a waveguide optical switch, a semiconductor
optical amplifier optical switch, and the like.
[0054] The optical switching apparatus provided in this embodiment
of this application includes the L first wavelength division
multiplexers/demultiplexers and the L second wavelength division
multiplexers/demultiplexers. Each wavelength division
multiplexer/demultiplexer has a signal light port and a remaining
multiplexing port. In this way, laser light may be input to the
remaining multiplexing port of the L first wavelength division
multiplexers/demultiplexers by the beam generation apparatus, and
then the first optical switch inputs the received laser light to
the demultiplexing ports of the L second wavelength division
multiplexers/demultiplexers. Then, any second wavelength division
multiplexer/demultiplexer that receives the laser light and that is
in the L second wavelength division multiplexers/demultiplexers
sends the received laser light through a remaining multiplexing
port of the second wavelength division multiplexer/demultiplexer to
the detection apparatus, so that the detection apparatus obtains an
output power of the output laser light. In comparison with the
conventional technology, the optical switching apparatus provided
in this embodiment of this application can still obtain the output
power of the laser light when there is no signal light, so as to
obtain an insertion loss of the first optical switch based on an
input power of the laser light and the output power of the laser
light. In this way, in scenarios of channel closed-loop, power-on
self-test, and unused-channel detection, the insertion loss of the
first optical switch can still be obtained even if there is no
service light on the channel.
[0055] Optionally, the first optical switch 201 in this embodiment
of this application is configured to establish and switch a
pass-through channel, a wavelength-adding channel, and a
wavelength-dropping channel.
[0056] It should be understood that, in this embodiment of this
application, signal light and detection light that have a same
wavelength are output through different demultiplexing ports.
However, when the wavelength of the signal light and the wavelength
of the detection light satisfy a specific relationship, the signal
light and the detection light that have the same wavelength may be
input through different multiplexing ports, and output through a
same demultiplexing port.
[0057] Generally, detection light with different wavelengths may be
input through a same multiplexing port or through different
multiplexing ports. Signal light with different wavelengths may be
input through a same signal light port.
[0058] For example, the first wavelength division
multiplexer/demultiplexer 202 has three multiplexing ports. If a
multiplexing port 1 is a signal light port, and a multiplexing port
2 and a multiplexing port 3 are detection light ports, signal light
with a wavelength of .lamda..sub.1, signal light with a wavelength
of .lamda..sub.2, signal light with a wavelength of .lamda..sub.3,
. . . , and signal light with a wavelength of may be input through
the multiplexing port 1. Detection light with a wavelength of
.lamda.'.sub.1 and detection light with a wavelength of
.lamda.'.sub.2 are input through the multiplexing port 2, detection
light with a wavelength of .lamda.'.sub.3, . . . , and detection
light with a wavelength of .lamda.'.sub.N are input through the
multiplexing port 3. Alternatively, detection light with a
wavelength of .lamda.'.sub.1, detection light with a wavelength of
.lamda.'.sub.2, detection light with a wavelength of
.lamda.'.sub.3, . . . , and detection light with a wavelength of
.lamda.'.sub.N are input through the multiplexing port 3 or the
multiplexing port 2.
[0059] For example, as shown in FIG. 7, the signal light with the
wavelength of .lamda..sub.1, the signal light with the wavelength
of .lamda..sub.2, the signal light with the wavelength of
.lamda..sub.3, . . . , and the signal light with the wavelength of
are input through the multiplexing port 2021 of the first
wavelength division multiplexer/demultiplexer 202. The detection
light with the wavelength of .lamda.'.sub.1, the detection light
with the wavelength of .lamda.'.sub.2, the detection light with the
wavelength of .lamda.'.sub.3, . . . , and the detection light with
the wavelength of .lamda.'.sub.N are input through the multiplexing
port 2022 of the first wavelength division
multiplexer/demultiplexer 202. Then, the signal light with the
wavelength of .lamda..sub.1 and the detection light with the
wavelength of .lamda.'.sub.1 are output through the demultiplexing
port 1. The signal light with the wavelength of .lamda..sub.2 and
the detection light with the wavelength of .lamda.'.sub.2 are
output through the demultiplexing port 2. The signal light with the
wavelength of .lamda.3 and the detection light with the wavelength
of .lamda.'.sub.3 are output through the demultiplexing port 3. The
signal light with the wavelength of and the detection light with
the wavelength of .lamda.'.sub.N are output through a
demultiplexing port N.
[0060] It should be understood that, in FIG. 7, in this embodiment
of this application, signal light with a wavelength of
.lamda..sub.4 is input through a demultiplexing port i, and may be
output through the multiplexing port 2021. A power of signal light
output through the multiplexing port 2022 is very small (crosstalk
light) or there is no signal light. The signal light with the
wavelength of .lamda..sub.4 is input through a demultiplexing port
j (j.noteq.i), and a power of light output through the multiplexing
port 2021 is very small (crosstalk light) or there is no light.
[0061] Detection light with a wavelength of .lamda.'.sub.i is input
through the demultiplexing port i, and may be output through the
multiplexing port 2022. A power of the detection light output
through the multiplexing port 2021 is very small (crosstalk light)
or there is no detection light. The detection light with the
wavelength of .lamda.'.sub.i is input through the demultiplexing
port j (j.noteq.i), and a power of light output through the
multiplexing port 2032 is very small (crosstalk light) or there is
no detection light. j is 1, . . . , or N. The wavelength division
multiplexer/demultiplexer is a wavelength-related component that is
made according to a principle of interference. Only laser light
with a specific wavelength can pass through a transmission path
from a multiplexing port to a demultiplexing port. Similarly, only
laser light with a specific wavelength can pass through a
transmission path from a demultiplexing port to a multiplexing
port.
[0062] According to the foregoing relationship, it is clear that
.lamda..sub.i and .lamda.'.sub.i cannot be the same. However, a set
from .lamda..sub.1 to may be the same as or different from a set
from .lamda.'.sub.1 to .lamda.'.sub.N.
[0063] It should be noted that, in this embodiment of this
application, one multiplexing port and one demultiplexing port may
form one transmission path. In other words, if there are X
multiplexing ports and Y demultiplexing ports, X*Y transmission
paths may be formed. One demultiplexing port and a multiplexing
port that serves as a signal light port may form a transmission
path, or one demultiplexing port and a multiplexing port that
serves as a detection light port may form a transmission path. For
example, in FIG. 7, the multiplexing port 2021 and the
demultiplexing port 1 and the multiplexing port 2022 and the
demultiplexing port 1 form two transmission paths. In this case,
the signal light with the wavelength of .lamda..sub.1 input through
the multiplexing port 2021 and the detection light with the
wavelength of .lamda.'.sub.1 input through the multiplexing port
2022 may separately be output through the demultiplexing port
1.
[0064] In a first optional implementation, the L first wavelength
division multiplexers/demultiplexers 202 may share one beam
generation apparatus 204. In this case, as shown in FIG. 8, the
beam generation apparatus 204 in this embodiment of this
application includes a tunable laser (TL) 2041 and a second optical
switch 2042.
[0065] The second optical switch 2042 is connected to both the
tunable laser 2041 and the remaining multiplexing port of the first
wavelength division multiplexer/demultiplexer 202, and is
configured to switch laser light, output by the tunable laser 2041,
to a target multiplexing port of the first wavelength division
multiplexer/demultiplexer 202.
[0066] It should be understood that the second optical switch 2042
is configured to select a first wavelength division
multiplexer/demultiplexer 202 in the L first wavelength division
multiplexers/demultiplexers 202 to which laser light generated by
the tunable laser 2041 is to be switched. That is, the second
optical switch 2042 is configured to select a first wavelength
division multiplexer/demultiplexer 202 in the L first wavelength
division multiplexers/demultiplexers 202, where laser light that is
generated by the tunable laser 2041 and that has a same wavelength
is sequentially input to the selected first wavelength division
multiplexer/demultiplexer 202.
[0067] For example, the second optical switch 2042 may be a 1*T
coupler or a 1*T optical switch, where T is a positive integer.
[0068] It should be understood that, when the second optical switch
2042 is the 1*T coupler, the second optical switch 2042 may
sequentially input laser light that has different wavelengths to
the first wavelength division multiplexer/demultiplexer 202 by
using a second example described below.
[0069] For example, when the L first wavelength division
multiplexers/demultiplexers 202 may share one beam generation
apparatus 204, in one aspect, in this embodiment of this
application, the tunable laser 2041 generates laser light with one
wavelength each time, and then the second optical switch 2042
sequentially inputs the laser light that has the same wavelength
and that is generated by the tunable laser 2041 each time to the L
first wavelength division multiplexers/demultiplexers 202.
Alternatively, in another aspect, the second optical switch 2042 is
adjusted, so that the second optical switch 2042 is first switched
to the multiplexing port 2022 of the first wavelength division
multiplexer/demultiplexer 202, and in this case, the tunable laser
2041 generates detection light with wavelengths from .lamda.'.sub.1
to .lamda.'.sub.N. Then the detection light with the wavelengths
from .lamda.'.sub.1 to .lamda.'.sub.N is sequentially input to the
multiplexing port 2022 of the first wavelength division
multiplexer/demultiplexer 202 to which the second optical switch
2042 is switched.
[0070] In a first example, in a working process of the beam
generation apparatus 204, that the generated laser light is
detection light is used as an example, and the tunable laser 2041
generates the detection light with the wavelength of
.lamda.'.sub.1. The second optical switch 2042 switches the
detection light with the wavelength of .lamda.'.sub.1 to a
multiplexing port 2022 of the first wavelength division
multiplexer/demultiplexer 21, then switches the detection light
with the wavelength of .lamda.'.sub.1 to a multiplexing port 2022
of the first wavelength division multiplexer/demultiplexer 22, . .
. , and switches the detection light with the wavelength of
.lamda.'.sub.1 to a multiplexing port 2022 of the first wavelength
division multiplexer/demultiplexer 2L. If the beam generation
apparatus 204 further generates the detection light with the
wavelength of .lamda.'.sub.2, the second optical switch 2042
sequentially switches the detection light with the wavelength of
.lamda.'.sub.2 to the first wavelength division
multiplexer/demultiplexer 21, . . . , and the first wavelength
division multiplexer/demultiplexer 2L. That is, an objective of the
second optical switch 2042 is to sequentially switch detection
light that has any wavelength and that is generated by the beam
generation apparatus 204 to the L first wavelength division
multiplexers/demultiplexers 202.
[0071] In the second example, the second optical switch 2042 is
first adjusted, so that the second optical switch 2042 is switched
to the multiplexing port 2022 of the first wavelength division
multiplexer/demultiplexer 21, and then the tunable laser 2041
sequentially generates the detection light with the wavelengths
from .lamda.'.sub.1 to .lamda.'.sub.N. Because the second optical
switch 2042 is switched to the multiplexing port 2022 of the first
wavelength division multiplexer/demultiplexer 21, in this case, the
detection light that has the wavelengths from .lamda.'.sub.1 to
.lamda.'.sub.N and that is generated by the tunable laser 2041 is
sequentially input to the multiplexing port 2022 of the first
wavelength division multiplexer/demultiplexer 21. Then, the second
optical switch 2042 is adjusted, so that the second optical switch
2042 is switched to the multiplexing port 2022 of the first
wavelength division multiplexer/demultiplexer 22, and then the
tunable laser 2041 sequentially generates the detection light with
the wavelengths from .lamda.'.sub.1 to .lamda.'.sub.N. Because the
second optical switch 2042 is switched to the multiplexing port
2022 of the first wavelength division multiplexer/demultiplexer 22,
in this case, the detection light that has the wavelengths from
.lamda.'.sub.1 to .lamda.'.sub.N and that is generated by the
tunable laser 2041 is sequentially input to the multiplexing port
2022 of the first wavelength division multiplexer/demultiplexer 22.
The rest can be deducted by analogy, and the detection light with
the wavelengths from .lamda.'.sub.1 to .lamda.'.sub.N is
sequentially input to each first wavelength division
multiplexer/demultiplexer in the L first wavelength division
multiplexers/demultiplexers.
[0072] In a second optional implementation, the L second wavelength
division multiplexers/demultiplexers 203 may share one detection
apparatus 205. In this case, as shown in FIG. 8, the detection
apparatus 205 further includes a detector 2051 and a coupler 2052.
The coupler 2052 is connected to both the detector 2051 and the
remaining multiplexing port of the second wavelength division
multiplexer/demultiplexer 203, and is configured to couple, to the
detector 2051, laser light output through the remaining
multiplexing port of the second wavelength division
multiplexer/demultiplexer.
[0073] It should be understood that the coupler 2052 sequentially
couples, to the detector 2051, laser light output through a
remaining multiplexing port of each second wavelength division
multiplexer/demultiplexer 203 in the L second wavelength division
multiplexers/demultiplexers 203.
[0074] For example, if the coupler 2052 first receives laser light
output through a remaining multiplexing port of a second wavelength
division multiplexer/demultiplexer 203, the coupler 2052 first
couples, to the detector 2051, the laser light output through the
remaining multiplexing port of the second wavelength division
multiplexer/demultiplexer 203, so that the detector 2051 may detect
an output power of the laser light output through the remaining
multiplexing port of each second wavelength division
multiplexer/demultiplexer 203.
[0075] It should be understood that the detector 2051 is configured
to obtain an output power of laser light of each wavelength in
laser light that has different wavelengths and that is output
through the remaining multiplexing port of each second wavelength
division multiplexer/demultiplexer 203.
[0076] For example, if the second wavelength division
multiplexer/demultiplexer 31 outputs laser light with a wavelength
of .lamda.'.sub.1, the coupler 2052 couples the laser light with
the wavelength of .lamda.'.sub.1 to the detector 2051, and the
detector 2051 detects an output power of the laser light with the
wavelength of .lamda.'.sub.1. If the second wavelength division
multiplexer/demultiplexer 31 outputs laser light with a wavelength
of .lamda.'.sub.2, the coupler 2052 couples the laser light with
the wavelength of .lamda.'.sub.2 to the detector 2051, and the
detector 2051 detects an output power of the laser light with the
wavelength of .lamda.'.sub.2.
[0077] For example, the coupler 2052 may be a 1*T optical switch or
a 1*T coupler.
[0078] It should be understood that, in this embodiment of this
application, an optical switch with 1*a plurality of ports may be
replaced with a coupler with a same quantity of ports based on a
system feature and a detection requirement. The coupler with 1*a
plurality of ports may be replaced with an optical switch with a
same quantity of ports based on a system feature and a detection
requirement. However, if a coupler is used in the detection
apparatus, the second optical switch in the beam generation
apparatus 204 needs to be a 1*T optical switch. For example, the
coupler 2052 may be a 1*T optical switch, and the second optical
switch may be a 1*T optical switch. The coupler 2052 may be a 1*T
coupler, and the second optical switch may be a 1*T optical switch.
The coupler 2052 may be a 1*T optical switch, and the second
optical switch may be a 1*T coupler.
[0079] Optionally, as shown in FIG. 8, in this embodiment of this
application, when the L first wavelength division
multiplexers/demultiplexers 202 share one beam generation apparatus
204, and the L second wavelength division
multiplexers/demultiplexers 203 share one detection apparatus 205,
the tunable laser 2041, the second optical switch 2042, the coupler
2052, and the detector 2051 in this embodiment of this application
may be made into an independent detection board.
[0080] Specifically, when the optical switching apparatus uses a
structure shown in FIG. 8, an insertion loss of signal light with a
wavelength of .lamda..sub.i on a pass-through channel in the first
optical switch may be detected. For example, the 1*T second optical
switch 2042 of an output port of the tunable laser 2041 is first
controlled to be switched to a multiplexing port 2022 of any first
wavelength division multiplexer/demultiplexer 202 (the first
wavelength division multiplexer/demultiplexer 21 is used as an
example), so that the tunable laser 2041 is connected to the
multiplexing port 2022 of the first wavelength division
multiplexer/demultiplexer 21. Then, the tunable laser 2041 is
adjusted to output detection light with a wavelength of
.lamda.'.sub.i. According to a pass-through channel detection
principle described in FIG. 3, after the detection light with the
wavelength of .lamda.'.sub.i is input to the multiplexing port 2022
of the first wavelength division multiplexer/demultiplexer 21, the
detection light with the wavelength of .lamda.'.sub.i is input to
the first optical switch 201 through one demultiplexing port of the
first wavelength division multiplexer/demultiplexer 21. Then, the
first optical switch 201 selects one second wavelength division
multiplexer/demultiplexer (the second wavelength division
multiplexer/demultiplexer 32 is used as an example). The detection
light with the wavelength of .lamda.'.sub.i enters the second
wavelength division multiplexer/demultiplexer 32 through one
demultiplexing port of the second wavelength division
multiplexer/demultiplexer 32, is output through a multiplexing port
2032 of the second wavelength division multiplexer/demultiplexer
32, and enters the detector 2051 after passing through the 1*T
coupler 2052. Then, the detector 2051 detects an output power of
the received detection light with the wavelength of .lamda.'.sub.i.
Finally, based on the output power of the detection light with the
wavelength of .lamda.'.sub.i and an input power of the detection
light with the wavelength of .lamda.'.sub.i, an insertion loss 1 of
the detection light with the wavelength of .lamda.'.sub.i on the
pass-through channel may be calculated. By subtracting an insertion
loss of components, other than the first optical switch, through
which the detection light with the wavelength of .lamda.'.sub.i
passes on a trail (that is, from the first wavelength division
multiplexer/demultiplexer 21 to the detector 2051) of the
pass-through channel from the insertion loss 1 of the detection
light with the wavelength of .lamda.'.sub.i on the pass-through
channel, an insertion loss of the detection light with the
wavelength of .lamda.'.sub.i in the first optical switch can be
obtained. It may be approximately considered that the insertion
loss of the detection light with the wavelength of .lamda.'.sub.i
in the first optical switch is the insertion loss of the signal
light with the wavelength of .lamda..sub.i on the pass-through
channel in the first optical switch.
[0081] It should be understood that the second optical switch 2042
may switch the detection light with the wavelength of
.lamda.'.sub.i to different first wavelength division
multiplexers/demultiplexers 202, so that the detector 2051 obtains
output powers of the detection light with different wavelengths on
the pass-through channel.
[0082] In another optional implementation, to flexibly control
laser light input to each first wavelength division
multiplexer/demultiplexer 202 in the L first wavelength division
multiplexers/demultiplexers 202, one first tunable laser may be
configured for each first wavelength division
multiplexer/demultiplexer 202. As shown in FIG. 9, a difference
between FIG. 9 and FIG. 8 is: The beam generation apparatus 204
includes a plurality of first tunable lasers (for example, the beam
generation apparatus 204 includes L first tunable lasers, and a
first tunable laser 41, a first tunable laser 42, . . . , and a
first tunable laser 4L are used as an example.) Each first tunable
laser in the plurality of first tunable lasers is connected to one
multiplexing port other than the signal light port of the L first
wavelength division multiplexers/demultiplexers.
[0083] For example, as shown in FIG. 9, the first tunable laser 41
is connected to the multiplexing port 2022 of the first wavelength
division multiplexer/demultiplexer 21. The first tunable laser 42
is connected to the multiplexing port 2022 of the first wavelength
division multiplexer/demultiplexer 22. The first tunable laser 4L
is connected to the multiplexing port 2022 of the first wavelength
division multiplexer/demultiplexer 2L.
[0084] In a structure shown in FIG. 9, any first tunable laser is
configured to sequentially generate laser light with different
wavelengths, and then sequentially input the laser light with
different wavelengths to a first wavelength division
multiplexer/demultiplexer 202 connected to the first tunable
laser.
[0085] For example, in FIG. 9, the first tunable laser 41 is
configured to sequentially generate detection light with
wavelengths from .lamda.'.sub.1 to .lamda.'.sub.N, so that the
first wavelength division multiplexer/demultiplexer connected to
the first tunable laser 41 can sequentially receive the detection
light with the wavelengths from .lamda.'.sub.1 to
.lamda.'.sub.N.
[0086] Further optionally, to accurately obtain an output power of
laser light output by each second wavelength division
multiplexer/demultiplexer 203 in the L second wavelength division
multiplexers/demultiplexers 203, one detector may be configured for
each second wavelength division multiplexer/demultiplexer 203. In
this case, the detection apparatus 205 includes a plurality of
detectors. For example, as shown in FIG. 9, a detector 51, a
detector 52, . . . , and a detector 5L are included. As shown in
FIG. 9, each detector in the plurality of detectors is connected to
one multiplexing port other than a signal light port of a second
wavelength division multiplexer/demultiplexer.
[0087] The detector in the embodiments of this application may be a
photodetector (PD).
[0088] For example, as shown in FIG. 9, a multiplexing port 2032 of
the second wavelength division multiplexer/demultiplexer 31 is
connected to the detector 51. The multiplexing port 2032 of the
second wavelength division multiplexer/demultiplexer 32 is
connected to the detector 52. A multiplexing port 2032 of the
second wavelength division multiplexer/demultiplexer 3L is
connected to the detector 5L.
[0089] It should be understood that any detector in FIG. 9 is
configured to detect an output power of laser light of each
wavelength in laser light that has different wavelengths and that
is output by a second wavelength division multiplexer/demultiplexer
connected to the detector.
[0090] It should be noted that, in this embodiment of this
application, the optical switching apparatus in any one of the
accompanying drawings FIG. 6 to FIG. 9 may calculate an output
power of laser light output on the pass-through channel. When
pass-through channel detection is implemented, a transmission
direction of signal light input through a signal light port of any
first wavelength division multiplexer/demultiplexer 202 in the L
first wavelength division multiplexers/demultiplexers 202 is the
same as or may be opposite to a transmission direction of detection
light input through a remaining multiplexing port. When the optical
switching apparatus may calculate the output power of the laser
light output on the pass-through channel, the beam generation
apparatus 204 provides laser light with a wavelength of
.lamda.'.sub.i to any first wavelength division
multiplexer/demultiplexer 202. The laser light with the wavelength
of .lamda.'.sub.i enters the any first wavelength division
multiplexer/demultiplexer 202 through a multiplexing port 2022 of
the any first wavelength division multiplexer/demultiplexer 202,
and then is input to the first optical switch 201 through a
demultiplexing port of the any first wavelength division
multiplexer/demultiplexer 202. After the first optical switch 201
selects one second wavelength division multiplexer/demultiplexer
203 for the laser light with the wavelength of .lamda.'.sub.i, the
laser light with the wavelength of .lamda.'.sub.i is input to a
demultiplexing port of the selected second wavelength division
multiplexer/demultiplexer 203, and enters the second wavelength
division multiplexer/demultiplexer 203. Then, the laser light with
the wavelength of .lamda.'.sub.i is output through a multiplexing
port 2032 of the second wavelength division
multiplexer/demultiplexer 203 to the detection apparatus 205.
[0091] Specifically, when the optical switching apparatus uses the
structure shown in FIG. 9, a difference between the structure in
which an insertion loss of signal light with a wavelength of
.lamda..sub.i on the pass-through channel is calculated and the
structure shown in FIG. 8 is: The first tunable laser 41 is used as
an example. The first tunable laser 41 in FIG. 9 is configured to
input detection light with a wavelength of .lamda.'.sub.i to a
multiplexing port 2022 of a first wavelength division
multiplexer/demultiplexer 21 connected to the first tunable laser
41. According to a pass-through channel detection principle
described in FIG. 3, the first wavelength division
multiplexer/demultiplexer 21 that receives the detection light with
the wavelength of .lamda.'.sub.i inputs the detection light with
the wavelength of .lamda.'.sub.i through a demultiplexing port 2023
to the first optical switch 201. After selecting one second
wavelength division multiplexer/demultiplexer (for example, the
second wavelength division multiplexer/demultiplexer 32), the first
optical switch 201 inputs the detection light with the wavelength
of .lamda.'.sub.i to a demultiplexing port 2033 of the selected
second wavelength division multiplexer/demultiplexer 32. Then, the
detection light with the wavelength of .lamda.'.sub.i is output
through the multiplexing port 2032 of the second wavelength
division multiplexer/demultiplexer 32, and is received by the
detector 52 connected to the second wavelength division
multiplexer/demultiplexer 32. The detector 52 detects an output
power of the received detection light with the wavelength of
.lamda.'.sub.i. In this way, based on an input power that is of the
detection light with the wavelength of .lamda.'.sub.i and that is
provided by the first tunable laser 41 and the output power of the
detection light with the wavelength of .lamda.'.sub.i, an insertion
loss 1 of the detection light with the wavelength of .lamda.'.sub.i
on the pass-through channel may be calculated. By subtracting an
insertion loss of components, other than the first optical switch,
through which the detection light with the wavelength of
.lamda.'.sub.i passes on an optical path in FIG. 9 from the
insertion loss 1, an insertion loss of the detection light with the
wavelength of .lamda.'.sub.i on the pass-through channel in the
first optical switch can be obtained. Because the insertion loss of
the first optical switch is insensitive to a wavelength, it may be
approximately considered that the insertion loss of the detection
light with the wavelength of .lamda.'.sub.i on the pass-through
channel in the first optical switch is the insertion loss of the
signal light with the wavelength of .lamda..sub.i on the
pass-through channel in the first optical switch. Alternatively, it
may be considered that the insertion loss 1 of the detection light
with the wavelength of .lamda.'.sub.i on the pass-through channel
is the insertion loss of the signal light with the wavelength of
.lamda..sub.i on the pass-through channel.
[0092] Optionally, to implement insertion loss detection on a
wavelength-adding channel or a wavelength-dropping channel, the
first optical switch 201 provided in this embodiment of this
application further includes M first tributary ports 206, and the
optical switching apparatus further includes a third optical switch
2043. The third optical switch 2043 is connected to both the beam
generation apparatus 204 and the M first tributary ports 206, where
M is a positive integer.
[0093] For example, in a structure shown in FIG. 10, the third
optical switch 2043 is connected to both the second optical switch
2042 and the M first tributary ports 206. The beam generation
apparatus 204 is configured to provide laser light for the M first
tributary ports 206.
[0094] For example, the third optical switch 2043 is a 1*M optical
switch or a 1*M coupler.
[0095] During wavelength-adding channel detection, the second
optical switch 2042 is configured to switch laser light from the
tunable laser 2041 to the third optical switch 2043. The third
optical switch 2043 is configured to select a first tributary port
in the M first tributary ports 206, where the laser light from the
tunable laser 2041 is input to the selected first tributary port.
Finally, laser light that has different wavelengths and that is
generated by the tunable laser 2041 is sequentially input to each
first tributary port.
[0096] It should be understood that, for example, the third optical
switch 2043 is a 1*M coupler, and if the tunable laser 2041
sequentially generates detection light with wavelengths from
.lamda.'.sub.1 to .lamda.'.sub.N, the third optical switch 2043 may
sequentially input the detection light with the wavelengths from
.lamda.'.sub.1 to .lamda.'.sub.N to a same first tributary port. In
this case, the third optical switch 2043 is first switched to one
first tributary port, and after the detection light with the
wavelengths from .lamda.'.sub.1 to .lamda.'.sub.N is input to the
first tributary port, the third optical switch 2043 is switched to
another first tributary port. Then, the detection light that has
the wavelengths from .lamda.'.sub.1 to .lamda.'.sub.N and that is
sequentially generated by the tunable laser 2041 is input to the
another first tributary port.
[0097] If the tunable laser 2041 inputs detection light that has a
same wavelength each time, the third optical switch 2043 may
sequentially input the detection light that has the same wavelength
to the M first tributary ports 206.
[0098] It should be noted that the M first tributary ports 206 may
be located on a same tributary board, or may be located on a
plurality of tributary boards. When the M first tributary ports 206
are located on a same tributary board, to reduce costs and a volume
of the optical switching apparatus, the M first tributary ports 206
may share one third optical switch 2043.
[0099] When the M first tributary ports 206 are located on a
plurality of tributary boards, a sum of quantities of first
tributary ports 206 distributed on the plurality of tributary
boards is equal to M. For example, a quantity of the plurality of
tributary boards is P, and a quantity of first tributary ports 206
distributed on each tributary board is Q. It should be understood
that quantities of first tributary ports 206 on different tributary
boards may be the same or may be different. However, it needs to be
ensured that a sum of quantities of all first tributary ports 206
on the P tributary boards is M.
[0100] If the M first tributary ports 206 are located on the P
tributary boards, and each tributary board includes Q first
tributary ports 206, the P tributary boards may share one third
optical switch 2043, or each tributary board may be connected to
one optical switch. In this case, the third optical switch 2043
includes P optical switches 20431. Each of the P optical switches
20431 is connected to the beam generation apparatus 204 and one of
the P tributary boards. The beam generation apparatus 204 is
configured to input generated laser light to any optical switch
20431 in the P optical switches 20431. The optical switch 20431
that receives the laser light from the beam generation apparatus
204 is configured to select a first tributary port 206 on a
tributary board connected to the optical switch 20431, where the
received laser light is input to the selected first tributary port
206. In this case, the optical switch 20431 may be a 1*Q optical
switch.
[0101] It should be understood that the M first tributary ports 206
may share one first beam generation apparatus. Certainly, each M
first tributary port 206 in the M first tributary ports 206 may
alternatively be connected to one tunable laser. The L first
wavelength division multiplexers/demultiplexers share one second
beam generation apparatus. The second beam generation apparatus and
the first beam generation apparatus are different beam generation
apparatuses. It should be understood that, in FIG. 10, for example,
the second beam generation apparatus and the first beam generation
apparatus are a same beam generation apparatus. In other words, the
M first tributary ports 206 and the L first wavelength division
multiplexers/demultiplexers 202 share one beam generation apparatus
204.
[0102] To flexibly input laser light to the M first tributary ports
206, in this embodiment of this application, one second tunable
laser 207 may be further configured for the M first tributary ports
206. In this case, in a structure shown in FIG. 11, the optical
switching apparatus in this embodiment of this application further
includes a second tunable laser 208 and a fifth optical switch 209.
The fifth optical switch 209 is connected to both the second
tunable laser 208 and the M first tributary ports 206. The fifth
optical switch 209 is configured to select a first tributary port
206 to which laser light from the second tunable laser 208 is
switched.
[0103] It should be understood that a difference between FIG. 10
and FIG. 11 or FIG. 12 is: In FIG. 10, the M first tributary ports
206 and the L first wavelength division multiplexers/demultiplexers
202 share one beam generation apparatus. In FIG. 11, the M first
tributary ports 206 provide laser light by using the second tunable
laser 208, and the L first wavelength division
multiplexers/demultiplexers 202 provide laser light by using a
tunable laser. In FIG. 12, the M first tributary ports 206 provide
laser light by using the second tunable laser 208, and each first
wavelength division multiplexer/demultiplexer 202 in the L first
wavelength division multiplexers/demultiplexers 202 provides laser
light by using a connected first tunable laser.
[0104] Optionally, for the structure shown in FIG. 11 or a
structure shown in FIG. 12, if the M first tributary ports 206 are
located on P tributary boards, and each tributary board includes Q
first tributary ports 206, for a structure of the fifth optical
switch, refer to the structure of the third optical switch 2043,
and details are not described herein again.
[0105] Optionally, in the structures shown in FIG. 10 to FIG. 12,
each tributary port in the M first tributary ports has one optical
splitter or one 1*2 coupler 207.
[0106] It should be understood that the optical splitter or the 1*2
coupler 207 that is connected in series to each tributary port is
configured to couple detection light to an optical path.
[0107] For example, the optical splitter or the coupler 207 has a
plurality of ports, one of the plurality of ports is a signal light
port 2061, and a remaining port 2062 may be used as a detection
light port. The remaining port 2062 is connected to the fifth
optical switch 209 or the third optical switch 2043.
[0108] When there is signal light, the signal light enters the
first optical switch through the signal light port 2061, and
detection light enters the first optical switch through the
remaining port 2062.
[0109] Specifically, when the optical switching apparatus uses the
structure shown in FIG. 10, in addition to calculating the
insertion loss of the signal light with the wavelength of
.lamda..sub.i on the pass-through channel in the first optical
switch, the optical switching apparatus may be further configured
to calculate the insertion loss of the signal light with the
wavelength of .lamda..sub.i on the wavelength-adding channel in the
first optical switch. A 1*T second optical switch 2042 of an output
port of the tunable laser 2041 and a 1*M third optical switch 2043
that corresponds to M first tributary ports of the
wavelength-adding channel are first controlled, so that the output
port of the tunable laser 2041 is connected to each optical
splitter on the first tributary ports. Then, the tunable laser 2041
is adjusted, so that the tunable laser 2041 outputs detection light
with a wavelength of .lamda.'.sub.i. According to a
wavelength-adding channel detection principle described in FIG. 4,
the detection light with the wavelength of .lamda.'.sub.i is output
through one multiplexing port other than a signal light port of one
first wavelength division multiplexer/demultiplexer 202 (the first
wavelength division multiplexer/demultiplexer 21 is used as an
example) or one second wavelength division
multiplexer/demultiplexer 203 (the second wavelength division
multiplexer/demultiplexer 31 is used as an example) corresponding
to the detected first tributary port 206. Then, the detection light
with the wavelength of .lamda.'.sub.i is coupled to a detector 2052
by a coupler 2051 connected to the first wavelength division
multiplexer/demultiplexer 21 or the second wavelength division
multiplexer/demultiplexer 31. The detector 2052 detects an output
power of the received detection light with the wavelength of
.lamda.'.sub.i. Then, a processor may calculate an insertion loss 1
of the detection light with the wavelength of .lamda.'.sub.i on the
entire wavelength-adding channel based on an input power of the
detection light with the wavelength of .lamda.'.sub.i and the
output power of the detection light with the wavelength of
.lamda.'.sub.i. By subtracting an insertion loss of components,
other than the first optical switch, through which the detection
light with the wavelength of .lamda.'.sub.i passes on an optical
path of the wavelength-adding channel from the insertion loss 1 of
the detection light with the wavelength of .lamda.'.sub.i on the
entire wavelength-adding channel, an insertion loss of the
detection light with the wavelength of .lamda.'.sub.i in the first
optical switch can be obtained. Because the first optical switch is
insensitive to a wavelength, it may be approximately considered
that the insertion loss of the detection light with the wavelength
of .lamda.'.sub.i in the first optical switch is an insertion loss
of signal light with a wavelength of .lamda..sub.i on the
wavelength-adding channel in the first optical switch.
Alternatively, it may be considered that the insertion loss 1 of
the detection light with the wavelength of .lamda.'.sub.i on the
entire wavelength-adding channel is an insertion loss of the signal
light with the wavelength of .lamda..sub.i on the entire
wavelength-adding channel.
[0110] Specifically, when the optical switching apparatus uses the
structure shown in FIG. 11 or FIG. 12, a difference between a
detection process of the insertion loss of the detection light with
the wavelength of .lamda.'.sub.i in the first optical switch and
that in FIG. 10 is: A 1*M fifth optical switch 209 corresponding to
a to-be-detected first tributary port is first controlled, so that
an output port of the second tunable laser 208 is connected to a
1*2 coupler on the to-be-detected first tributary port. For a
remaining process, refer to a process of how to detect the
insertion loss of the detection light with the wavelength of
.lamda.'.sub.i in the first optical switch in FIG. 10, and details
are not described herein again.
[0111] Optionally, when the structures shown in FIG. 10 to FIG. 12
include both a wavelength-adding channel and a pass-through
channel, and when the M first tributary ports 206 correspond to the
L first wavelength division multiplexers/demultiplexers 202, the
optical switching apparatus further includes a plurality of
circulators 210. A first port b of each circulator 210 in the
plurality of circulators 210 is connected to the beam generation
apparatus 204, a second port a of each circulator 210 is connected
to one multiplexing port 2022 other than the signal light port of
the first wavelength division multiplexer/demultiplexer 202, and a
third port c of each circulator 210 is connected to the detection
apparatus 205.
[0112] It should be understood that, on the wavelength-adding
channel, the laser light with the wavelength of .lamda.'.sub.i is
input through any first tributary port 206 to the first optical
switch 201. Then, after the first optical switch 201 selects one
first wavelength division multiplexer/demultiplexer 202 or one
second wavelength division multiplexer/demultiplexer 203, the first
optical switch 201 inputs the laser light with the wavelength of
.lamda.'.sub.i to the first wavelength division
multiplexer/demultiplexer 202 or a demultiplexing port with the
wavelength of .lamda.'.sub.i of the second wavelength division
multiplexer/demultiplexer 203.
[0113] It should be understood that, that the M first tributary
ports 206 correspond to the L first wavelength division
multiplexers/demultiplexers 202 may mean that on the
wavelength-adding channel, laser light output through any first
tributary port 206 in the M first tributary ports 206 is output
through a remaining multiplexing port 2022 of one of the L first
wavelength division multiplexers/demultiplexers 202.
[0114] It should be understood that a difference between FIG. 13
and FIG. 14 is: In a structure shown in FIG. 13, the first port b
of each circulator 210 is connected to the second optical switch
2042, and the third port c of each circulator 210 is connected to
the coupler 2051. In a structure shown in FIG. 14, the detection
apparatus 205 further includes L detectors, where each of the L
detectors is connected to a third port c of one circulator 210, and
the first port b of each circulator 210 is connected to a first
tunable laser.
[0115] It should be noted that the circulator 210 may be an optical
circulator. The circulator 210 is configured to separate laser
light input to the first wavelength division
multiplexer/demultiplexer 202 from laser light output from the
first wavelength division multiplexer/demultiplexer 202.
[0116] It should be understood that a difference between a process
in which the structure shown in FIG. 13 is used to detect the
insertion loss of the detection light with the wavelength of
.lamda.'.sub.i in the first optical switch and that in FIG. 10 is:
In FIG. 13, if one first wavelength division
multiplexer/demultiplexer 202 receives the detection light with the
wavelength of .lamda.'.sub.i, the detection light with the
wavelength of .lamda.'.sub.i is output through a multiplexing port
other than a signal light port of the first wavelength division
multiplexer/demultiplexer 202, enters the circulator 210 through
the port a of the circulator, and then enters the coupler 2051
through the port c of the circulator 210. For a same part between
FIG. 13 and FIG. 10, refer to the description in FIG. 10. Details
are not described herein again.
[0117] A difference between a detection process in which the
structure shown in FIG. 14 is used to detect the insertion loss of
the detection light with the wavelength of .lamda.'.sub.i in the
first optical switch and that in FIG. 11 or FIG. 12 is: If one
first wavelength division multiplexer/demultiplexer 202 receives
the detection light with the wavelength of .lamda.'.sub.i, the
detection light with the wavelength of .lamda.'.sub.i is output
through a multiplexing port other than a signal light port of the
first wavelength division multiplexer/demultiplexer 202, enters the
circulator 210 through the port a of the circulator, and then
enters the detector through the port c of the circulator 210. For a
same part between FIG. 14 and FIG. 11 or FIG. 12, refer to the
description in FIG. 11. Details are not described herein again.
[0118] It should be noted that, when the structures shown in FIG.
10 to FIG. 12 include both a wavelength-adding channel and a
pass-through channel, when the M first tributary ports 206
correspond to the L second wavelength division
multiplexers/demultiplexers 203, or when the optical switching
apparatus does not include a wavelength-adding channel, the
circulator 210 may not be disposed on the optical switching
apparatus.
[0119] Optionally, in an optional embodiment, as shown in FIG. 15
or FIG. 16, the first optical switch 201 further includes N second
tributary ports 211, and the optical switching apparatus further
includes a fourth optical switch 212. The fourth optical switch 212
is connected to both the beam generation apparatus 204 and the N
second tributary ports 211 of the first optical switch 201, where N
is a positive integer.
[0120] The fourth optical switch 212 is a 1*N optical switch or
coupler. It should be understood that a difference between FIG. 16
and FIG. 15 is: In FIG. 15, the N second tributary ports 211 and
the L first wavelength division multiplexers/demultiplexers 202
share one beam generation apparatus. For example, the N second
tributary ports 211 are connected to the second optical switch 2042
through the fourth optical switch 212. In FIG. 16, the optical
switching apparatus may further include a third tunable laser 213
and a sixth optical switch 214. The sixth optical switch 214 is
connected to the third tunable laser 213 and the N second tributary
ports 211. The third tunable laser 213 is configured to provide
laser light for the N second tributary ports 211. The N second
tributary ports 211 are configured to select a second tributary
port 211 that the laser light generated by the third tunable laser
213 enters.
[0121] It should be understood that, on a wavelength-dropping
channel, because a transmission direction of signal light input to
the first optical switch 201 and a transmission direction of
detection light input to the first optical switch 201 need to be
opposite, if the signal light is output through a second tributary
port 211, the detection light needs to be input through the second
tributary port 211. In this case, each second tributary port 211 is
provided with laser light by the third tunable laser 213. For the
wavelength-dropping channel, the detection light is transmitted
from a tributary port to a line port, and the transmission
direction of the detection light is opposite to the transmission
direction of the signal light. Therefore, the second tributary port
also needs to be connected to the third tunable laser 213 to input
the detection light.
[0122] In this embodiment of this application, the sixth optical
switch 214 may be a 1*N optical switch, and the fifth optical
switch 209 may be a 1*M optical switch.
[0123] It should be understood that any second tributary port 211
in the N second tributary ports 211 is configured to form a
wavelength-dropping channel with one of the L first wavelength
division multiplexers/demultiplexers 202. Alternatively, any second
tributary port 211 is configured to form a wavelength-dropping
channel with one of the L second wavelength division
multiplexers/demultiplexers 203.
[0124] It should be understood that, when both the wave-dropping
channel and the wave-adding channel exist in the optical switching
apparatus, the optical switching apparatus may include both N
second tributary ports and M first tributary ports. Alternatively,
a part of M first tributary ports are used as wavelength-adding
ports, and the other part of the M first tributary ports are used
as wavelength-dropping ports. In this case, N second tributary
ports may not be disposed. Alternatively, when the
wavelength-dropping channel and the wavelength-adding channel do
not exist at a same time in the optical switching apparatus, M
first tributary ports may be used as wave-adding ports when the
wave-adding channel exists. The M first tributary ports are used as
wavelength-dropping ports when the wavelength-dropping channel
exists. In this case, N second tributary ports may not be
disposed.
[0125] Optionally, in this embodiment of this application, an
optical splitter 207 may be connected in series to each second
tributary port.
[0126] A process in which a structure shown in FIG. 15 is used to
detect an insertion loss of the signal light with the wavelength of
.lamda..sub.i in the first optical switch may be specifically: When
an insertion loss of the signal light with the wavelength of
.lamda..sub.i in the wavelength-dropping channel needs to be
detected, a 1*T second optical switch 2042 of an output port of the
tunable laser 2041 and a 1*N fourth optical switch 212 that
corresponds to a to-be-detected second tributary port are first
controlled, so that the output port of the tunable laser is
connected to a 1*2 coupler 207 on the to-be-detected second
tributary port. Then, the tunable laser 2041 is adjusted, so that
the tunable laser 2041 outputs detection light with a wavelength of
According to a wavelength-dropping channel detection principle
described in FIG. 5, the detection light with the wavelength of
.lamda.'.sub.i is output through a multiplexing port other than a
signal light port of a second wavelength division
multiplexer/demultiplexer 203 corresponding to the to-be-detected
second tributary port, and enters the detector 2052 after passing
through a 1*T coupler 2051. The detector 2052 detects an output
power of the detection light with the wavelength of .lamda.'.sub.i.
Then, the processor may obtain an insertion loss 1 based on an
input power and the output power of the detection light that has
the wavelength of .lamda.'.sub.i and that is generated by the
tunable laser 2041. By subtracting an insertion loss of components,
other than the first optical switch 201, through which the
detection light with the wavelength of .lamda.'.sub.i passes on an
optical path of the wavelength-dropping channel from the insertion
loss 1, an insertion loss of the detection light with the
wavelength of .lamda.'.sub.i in the first optical switch can be
obtained. It may be approximately considered that the insertion
loss of the detection light with the wavelength of .lamda.'.sub.i
in the first optical switch is the insertion loss of the signal
light with the wavelength of .lamda..sub.i in the first optical
switch.
[0127] When a structure shown in FIG. 16 is used to detect an
insertion loss of the signal light with the wavelength of
.lamda..sub.i in the first optical switch, a difference between the
process and that in FIG. 15 is: A 1*N sixth optical switch 214
corresponding to a to-be-detected second tributary port is first
controlled, so that an output port of the third tunable laser 213
is connected to a 1*2 coupler 207 on the to-be-detected second
tributary port. Then, the third tunable laser 213 is adjusted, so
that the third tunable laser 213 outputs detection light with a
wavelength of .lamda.'.sub.i. For an optical path of the detection
light with the wavelength of .lamda.'.sub.i on the
wavelength-dropping channel, refer to the description in FIG. 15,
and details are not described herein again. In addition, in FIG.
16, an output power of the detection light with the wavelength of
.lamda.'.sub.i is detected by a detector connected to a second
wavelength division multiplexer/demultiplexer that receives the
detection light with the wavelength of an input power of the
detection light with the wavelength of .lamda.'.sub.i is provided
by the third tunable laser 213.
[0128] Optionally, as shown in FIG. 17, the first optical switch
further includes M first tributary ports 206. The optical switching
apparatus includes a multi-wavelength laser source, where a
plurality of output ports of the multi-wavelength laser source are
respectively connected to the M first tributary ports 206.
[0129] It should be understood that, in FIG. 17, for example, each
first wavelength division multiplexer/demultiplexer 202 in the L
first wavelength division multiplexers/demultiplexers 202 is
connected to one first tunable laser, and each second wavelength
division multiplexer/demultiplexer 203 in the L second wavelength
division multiplexers/demultiplexers 203 is connected to one
detector. In an actual process, when the plurality of output ports
of the multi-wavelength laser source are respectively connected to
the M first tributary ports 206, the L first wavelength division
multiplexers/demultiplexers 202 may share one beam generation
apparatus 204, and the L second wavelength division
multiplexers/demultiplexers 203 may also share one detection
apparatus 205. Details are not described herein again in this
embodiment of this application.
[0130] For example, the multi-wavelength laser source may be a
service board.
[0131] When an insertion loss of the detection light with the
wavelength of .lamda.'.sub.i on the wavelength-adding channel or
the wavelength-dropping channel is calculated by using a structure
shown in FIG. 17, reference may be specifically made to the
foregoing description of the related parts, and details are not
described herein again. A difference is that, in FIG. 17, the
detection light with the wavelength of .lamda.'.sub.i is generated
by a local service board.
[0132] In an actual detection process, based on a scenario
requirement, an optical switch connected to each first tributary
port 206 or each second tributary port 211 and a wavelength of the
tunable laser may be sequentially adjusted, so that insertion
losses of all to-be-detected channels in the optical switching
apparatus are detected in turn.
[0133] In the solution of this embodiment, a group of pass-through
channels corresponding to each second wavelength division
multiplexer/demultiplexer 203 and each group of wavelength-adding
channels or wavelength-dropping channels each have one tunable
laser. All group of channels may be detected in turn at a same
time. This can effectively reduce an in-turn detection time. In
addition, detection light on the pass-through channel does not pass
through the second optical switch 2042, and in-turn detection is
not limited by a switching time of the second optical switch 2042.
A fast tunable laser is selected, so that a fast speed of the
in-turn detection can be achieved.
[0134] It should be noted that, in an implementation process, one
first wavelength division multiplexer/demultiplexer 202 and one
second wavelength division multiplexer/demultiplexer 203 may be
manufactured on one circuit board, which is referred to as a line
board. One group of wavelength-adding ports and one group of
wavelength-dropping ports are manufactured on one circuit board,
which is referred to as a tributary board. The detector and the
tunable laser in the embodiments of this application may be
allocated to each tributary board or line board, so that
implementation is more convenient.
[0135] Optionally, the optical switching apparatus provided in this
embodiment of this application may further include a processor,
connected to an output port of the detection apparatus 205, and
configured to: obtain an input power of the laser light and the
output power that is of the laser light and that is obtained by the
detection apparatus 205, and determine an insertion loss of the
first optical switch 201 based on the output power of the laser
light and the input power of the laser light.
[0136] Specifically, the processor is specifically configured to
calculate an insertion loss 1 of the laser light on an entire
to-be-detected channel (the pass-through channel, the
wavelength-adding channel, or the wavelength-dropping channel)
based on the input power of the laser light and the output power
that is of the laser light and that is obtained by the detection
apparatus 205. By subtracting an insertion loss 2 of components
other than the first optical switch 201 from the insertion loss 1,
an insertion loss 3 of the laser light in the first optical switch
201 can be obtained. Because the insertion loss of the first
optical switch 201 is insensitive to a wavelength, it may be
approximately considered that the insertion loss 3 is an insertion
loss of signal light on the to-be-detected channel in the first
optical switch 201.
[0137] The processor in the embodiments of this application may be
a general-purpose central processing unit (CPU), a microprocessor,
an application-specific integrated circuit (ASIC), or one or more
integrated circuits configured to control program execution of the
solutions of this application. The input power can be obtained from
the beam generation apparatus, or may be preconfigured in the
processor. This is not limited in this embodiment of this
application.
[0138] Optionally, an embodiment of this application provides an
optical switching system. The optical switching system includes at
least two optical switching apparatuses shown in any one of FIG. 6
to FIG. 17. Any two optical switching apparatuses communicate with
each other through a line port.
[0139] It should be noted that reference may be made to each other
for the embodiments of this application. For example, for same or
similar steps, mutual reference may be made between the method
embodiment and the apparatus embodiment. This is not limited.
[0140] FIG. 18 is a schematic flowchart of a power calculation
method according to this application. The method may be used for an
optical switching apparatus, for example, any optical switching
apparatus shown in FIG. 6 to FIG. 17.
[0141] For example, when the method is used for a structure shown
in FIG. 6 (for a specific structure, refer to the description in
FIG. 6, and details are not described herein again), the method
includes the following steps.
[0142] Step 101: A beam generation apparatus 204 inputs first laser
light to a multiplexing port 2022 other than a signal light port in
a plurality of multiplexing ports of any first wavelength division
multiplexer/demultiplexer 202 in L first wavelength division
multiplexers/demultiplexers 202.
[0143] It should be understood that the beam generation apparatus
204 generates first laser light with one wavelength each time, and
then inputs the first laser light to the multiplexing port 2022
other than the signal light port in the plurality of multiplexing
ports of the any first wavelength division
multiplexer/demultiplexer 202 in the L first wavelength division
multiplexers/demultiplexers 202.
[0144] Step 102: The first wavelength division
multiplexer/demultiplexer 202 that receives the first laser light
inputs the first laser light through one of a plurality of
demultiplexing ports 2023 of the first wavelength division
multiplexer/demultiplexer 202 to a first optical switch 201.
[0145] Step 103: The first optical switch 201 inputs the first
laser light to a corresponding demultiplexing port 2033 of any
second wavelength division multiplexer/demultiplexer 203 in L
second wavelength division multiplexers/demultiplexers 203.
[0146] Step 104: The second wavelength division
multiplexer/demultiplexer 203 that receives the first laser light
inputs the first laser light through one multiplexing port 2032
other than a signal light port in a plurality of multiplexing ports
of the second wavelength division multiplexer/demultiplexer to a
detection apparatus 205.
[0147] Step 105: The detection apparatus 205 calculates an output
power of the first laser light.
[0148] According to the power calculation method provided in this
embodiment of this application, the L first wavelength division
multiplexers/demultiplexers and the L second wavelength division
multiplexers/demultiplexers are included. Each wavelength division
multiplexer/demultiplexer has a signal light port and a remaining
multiplexing port. In this way, laser light may be input to the
remaining multiplexing port of the L first wavelength division
multiplexers/demultiplexers by the beam generation apparatus, and
then the first optical switch inputs the received laser light to
the demultiplexing ports of the L second wavelength division
multiplexers/demultiplexers. Then, any second wavelength division
multiplexer/demultiplexer that receives the laser light and that is
in the L second wavelength division multiplexers/demultiplexers
sends the received laser light through a remaining multiplexing
port of the second wavelength division multiplexer/demultiplexer to
the detection apparatus, so that the detection apparatus obtains an
output power of the output laser light. In comparison with the
conventional technology, the optical switching apparatus provided
in this embodiment of this application can still obtain the output
power of the laser light when there is no signal light. Therefore,
an insertion loss of the first optical switch can be obtained based
on an input power of the laser light and the output power of the
laser light. In this way, in scenarios of channel closed-loop,
power-on self-test, and unused-channel detection, the insertion
loss of the first optical switch can still be obtained even if
there is no service light on the channel.
[0149] Optionally, when the optical switching apparatus uses the
structure shown in FIG. 8, step 101 may be specifically implemented
in the following manner: A tunable laser 2041 generates the first
laser light, and inputs the first laser light to a second optical
switch 2042. The second optical switch 2042 switches the first
laser light to a target multiplexing port of the any first
wavelength division multiplexer/demultiplexer 202.
[0150] It should be understood that, that the second optical switch
2042 switches the first laser light to a target multiplexing port
of the any first wavelength division multiplexer/demultiplexer 202
means that the second optical switch 2042 switches the first laser
light to one multiplexing port other than the signal light port of
the any first wavelength division multiplexer/demultiplexer
202.
[0151] It should be noted that, if there are two or more detection
light ports, a quantity of lasers should be the same as a quantity
of the detection light ports.
[0152] When the optical switching apparatus uses the structure
shown in FIG. 8, step 105 may be specifically implemented in the
following manner: A coupler 2052 couples, to a detector 2051, the
first laser light from the second wavelength division
multiplexer/demultiplexer 203. The detector 2051 detects an output
power of the first laser light output by the second wavelength
division multiplexer/demultiplexer 203.
[0153] It should be understood that if the coupler 2052 receives a
plurality of beams of first laser light from different second
wavelength division multiplexers/demultiplexers 203, the coupler
2052 sequentially couples, to the detector 2051, the first laser
light from each second wavelength division
multiplexer/demultiplexer 203. In this way, the detector 2051 can
each time detect an output power of the first laser light that is
from one second wavelength division multiplexer/demultiplexer
203.
[0154] Optionally, when the beam generation apparatus 204 uses the
structure shown in FIG. 9, step 101 may be specifically implemented
in the following manner: Each first tunable laser (for example, a
first tunable laser 41, a first tunable laser 42, . . . , or a
first tunable laser 4L) inputs the first laser light to a
multiplexing port connected to the first tunable laser.
[0155] For example, the first tunable laser 41 inputs the first
laser light to a multiplexing port 2022 of a first wavelength
division multiplexer/demultiplexer 21 connected to the first
tunable laser 41.
[0156] Optionally, when the detection apparatus 205 uses the
structure shown in FIG. 9, step 105 may be specifically implemented
in the following manner: Each detector detects an output power of
the first laser light output through a multiplexing port connected
to the detector.
[0157] For example, a detector 51 detects an output power of the
first laser light output through a multiplexing port 2032 of a
second wavelength division multiplexer/demultiplexer 31. A detector
52 detects an output power of the first laser light output through
a multiplexing port 2032 of a second wavelength division
multiplexer/demultiplexer 32.
[0158] Optionally, when the optical switching apparatus uses the
structure shown in FIG. 10, in other words, when the first optical
switch 201 further includes M first tributary ports 206, the
optical switching apparatus further includes a third optical switch
2043. The third optical switch 2043 is connected to both the beam
generation apparatus 204 and the M first tributary ports 206, where
M is a positive integer. As shown in FIG. 19A and FIG. 19B, the
method provided in this embodiment of this application further
includes the following steps.
[0159] Step 106: The beam generation apparatus 204 inputs second
laser light to the M first tributary ports 206 through the third
optical switch 2043.
[0160] Specifically, step 106 in FIG. 10 may be specifically
implemented in the following manner: The tunable laser 2041
generates the second laser light, and inputs the second laser light
to the second optical switch 2042. The second optical switch 2042
switches the second laser light to the third optical switch 2043.
The third optical switch 2043 selects one first tributary port 206
from the M first tributary ports 206, and inputs the second laser
light to the selected first tributary port 206.
[0161] Specifically, when an optical splitter or a coupler 207
exists on each first tributary port, the third optical switch 2043
inputs the second laser light to a detection light port of an
optical splitter or a coupler 207 that is connected in series to
the selected first tributary port 206.
[0162] Step 107: The first tributary port that receives the second
laser light inputs the second laser light to the first optical
switch 201.
[0163] Step 108: The first optical switch 201 inputs the second
laser light to a target demultiplexing port of one of the L first
wavelength division multiplexers/demultiplexers.
[0164] Step 109: The first wavelength division
multiplexer/demultiplexer that receives the second laser light
inputs the second laser light to the detection apparatus 205.
[0165] Step 110: The detection apparatus 205 obtains an output
power of the second laser light.
[0166] It should be understood that in the structure shown in FIG.
10, step 110 may be specifically implemented in the following
manner: The detector 2052 sequentially detects the output power of
the second laser light that is input to the detection apparatus and
that is output by the first wavelength division
multiplexer/demultiplexer.
[0167] In addition, on a wavelength-adding channel, step 109 may be
replaced in the following manner: A second wavelength division
multiplexer/demultiplexer that receives the second laser light
inputs the second laser light to the detection apparatus 205.
[0168] Optionally, when the optical switching apparatus uses the
structure shown in FIG. 11 or FIG. 12, step 106 provided in this
embodiment of this application may alternatively be replaced in the
following manner: A second tunable laser 208 inputs the second
laser light to the M first tributary ports 206 through a fifth
optical switch 209. When the optical switching apparatus uses the
structure shown in FIG. 12, in other words, when each first
wavelength division multiplexer/demultiplexer is connected to one
detector, step 109 may alternatively be replaced in the following
manner: A second wavelength division multiplexer/demultiplexer that
receives the second laser light inputs the second laser light to a
detector connected to the second wavelength division
multiplexer/demultiplexer.
[0169] Optionally, as shown in FIG. 13, when the M first tributary
ports 206 correspond to the L first wavelength division
multiplexers/demultiplexers 202, the optical switching apparatus
further includes a plurality of circulators 210. A first port of
each circulator 210 in the plurality of circulators 210 is
connected to the beam generation apparatus, a second port of each
circulator 210 is connected to one multiplexing port other than the
signal light port of the first wavelength division
multiplexer/demultiplexer, and a third port of each circulator 210
is connected to the detection apparatus 205. In this case, step 109
may be specifically implemented in the following manner: The
circulator receives the second laser light through the second port,
and inputs the second laser light to the detection apparatus 205
through the third port. For example, the circulator inputs the
second laser light through the third port to a coupler 2051, and
the coupler 2051 couples the second laser light to a detector
2052.
[0170] Optionally, when the L second wavelength division
multiplexers/demultiplexers correspond to the M first tributary
ports in this embodiment of this application, in other words, when
second laser light in any first tributary port in the M first
tributary ports is output from one of the L second wavelength
division multiplexers/demultiplexers, step 109 may alternatively be
replaced in the following manner: A second wavelength division
multiplexer/demultiplexer that receives the second laser light
inputs the second laser light to the detection apparatus.
[0171] Specifically, the first wavelength division
multiplexer/demultiplexer that receives the second laser light
inputs the second laser light to the coupler 2051, and the coupler
2051 couples, to the detector 2052, the received second laser light
from the first wavelength division multiplexer/demultiplexer.
[0172] Optionally, the method provided in this embodiment of this
application further includes: The M first tributary ports included
in the first optical switch receives laser light from a
multi-wavelength laser source.
[0173] Optionally, the method provided in this embodiment of this
application further includes:
[0174] A processor obtains an output power that is of the laser
light and that is obtained by the detection apparatus, and
calculates a power loss of the laser light based on an input power
of the laser light.
[0175] For example, the input power of the laser light can be
obtained from the beam generation apparatus.
[0176] For example, the processor obtains the output power that is
of the first laser light and that is obtained by the detection
apparatus, and calculates a power loss of the first laser based on
an input power of the first laser light.
[0177] For example, the processor obtains the output power that is
of the second laser light and that is obtained by the detection
apparatus, and calculates a power loss of the second laser based on
an input power of the second laser light.
[0178] It should be understood that, in this embodiment of this
application, the power loss of the first laser light may be an
insertion loss of the first laser light on a to-be-detected
channel.
[0179] Finally, it should be noted that the foregoing embodiments
are merely intended to describe the technical solutions of this
application, but not to limit this application. Although this
application is described in detail with reference to the foregoing
embodiments, persons of ordinary skill in the art should understand
that they may still make modifications to the technical solutions
described in the foregoing embodiments or make equivalent
replacements to some technical features thereof, without departing
from the spirit and scope of the technical solutions of the
embodiments of this application.
* * * * *